programming-examples/java/Data_Structures/Java Program to implement Dynamic Array.java

/*This is a Java Program to implement Dynamic Array. A dynamic array, growable array, resizable array, dynamic table, mutable array, or array list is a random access, variable-size list data structure that allows elements to be added or removed.*/

/**
 ** Java Program to implement Dynamic Array
 **/

import java.util.Scanner;
import java.util.ArrayList;

/** class DynamicArray */
class DynamicArray
{
    private ArrayList<String> al;

    /** constructor **/
    public DynamicArray()
    {
        al = new ArrayList<String>();
    }
    /** function to clear **/
    public void clear()
    {
        al.clear();
    }
    /** function to get size **/
    public int size()
    {
        return al.size();
    }
    /** function to insert element **/
    public void insert(String key)
    {
        al.add(key);
    }
    /** function to get element at index **/
    public String get(int index)
    {
        if (index >= al.size())
            return "";
        return al.get(index);
    }
    /** function to remove element at index **/
    public void remove(int index)
    {
        if (index >= al.size())
            return ;
        al.remove(index);
    }
    /** function to remove element **/
    public void remove(String key)
    {
        al.remove(key);
    }
    /** function to display array **/
    public void display()
    {
        System.out.println("\nDynamic Array : "+ al);
        System.out.println();
    }
}

/** Class DynamicArrayTest **/
public class DynamicArrayTest
{
    public static void main(String[] args)
    {
        Scanner scan = new Scanner(System.in);
        System.out.println("Dynamic Array Test\n");
        DynamicArray da = new DynamicArray();
        char ch;
        /*  Perform Dynamic Array operations */
        do
            {
                System.out.println("\nDynamic Array\n");
                System.out.println("1. insert ");
                System.out.println("2. remove by index");
                System.out.println("3. remove by val");
                System.out.println("4. clear");
                System.out.println("5. size");
                int choice = scan.nextInt();
                switch (choice)
                    {
                    case 1 :
                        System.out.println("Enter value to insert");
                        da.insert(scan.next() );
                        break;
                    case 2 :
                        System.out.println("Enter index");
                        da.remove(scan.nextInt() );
                        break;
                    case 3 :
                        System.out.println("Enter value");
                        da.remove(scan.next() );
                        break;
                    case 4 :
                        System.out.println("\nDynamic Array Cleared");
                        da.clear();
                        break;
                    case 5 :
                        System.out.println("\nSize = "+ da.size() );
                        break;
                    default :
                        System.out.println("Wrong Entry \n ");
                        break;
                    }
                da.display();
                System.out.println("\nDo you want to continue (Type y or n) \n");
                ch = scan.next().charAt(0);
            }
        while (ch == 'Y'|| ch == 'y');
    }
}

/*
Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
1
Enter value to insert
apple

Dynamic Array : [apple]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
1
Enter value to insert
mango

Dynamic Array : [apple, mango]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
1
Enter value to insert
banana

Dynamic Array : [apple, mango, banana]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
1
Enter value to insert
strawberry

Dynamic Array : [apple, mango, banana, strawberry]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
5

Size = 4

Dynamic Array : [apple, mango, banana, strawberry]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
2
Enter index
2

Dynamic Array : [apple, mango, strawberry]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
3
Enter value
strawberry

Dynamic Array : [apple, mango]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
5

Size = 2

Dynamic Array : [apple, mango]


Do you want to continue (Type y or n)

y

Dynamic Array

1. insert
2. remove by index
3. remove by val
4. clear
5. size
4

Dynamic Array Cleared

Dynamic Array : []


Do you want to continue (Type y or n)

n